From AustinWater: “November marks the beginning of Austin Water’s annual wastewater averaging period. The wastewater averaging period spans three consecutive billing periods beginning in mid-November and ending in mid-March. Check your utility bill or visit http://austinwater.org to find the dates for your wastewater averaging period.
Wastewater averaging is a way for you to save money. It is calculated during the winter months when most residential water goes directly into the sanitary sewer system versus being used for outdoor watering. This measurement determines the cap on the volume of wastewater you will be billed for each month for the next year. If there is outside watering during the wastewater averaging period, that water volume will also be included in the wastewater average. Avoid this by making sure your irrigation systems are turned off during your wastewater averaging period.
Visit http://waterwiseaustin.org for water conservation tips and to find out about rebate programs.”